Why wont the dog let puppies nurse?

She might have metritis (inflammation of the uterus), consult with a veterinarian as to make sure she does before giving her medication.

METRITIS (INFLAMMATION OF THE UTERUS)

Signs of this condition are as follows:

• fever
• foul smelling vaginal discharge
• listlessness
• loss of appetite
• no interest in the puppies
• decreased milk production

If these signs are noted, usually in the first day or two postpartum, a veterinarian should be consulted. Your dog may have retained a placenta or have suffered some trauma during delivery. Animals who have required assistance with delivery are often predisposed to metritis. She will likely need to be spayed.